With the rapid development of power electronics technology, the integration level of high-power devices such as IGBTs (insulated gate bipolar transistors), diodes and thyristors is getting higher and higher, the power density thereof is also getting larger and larger, and the heat generated during operation is getting more and more. In order to ensure the normal operation of a power device, heat must be dissipated timely and effectively. Because if the heat generated by the power device cannot be quickly dissipated in time, the temperature of chips in the power device will be increased, which, at best, will cause performance degradation, and shortening of service life and, at worst, will results in failure of the power device and burning and explosion of the chip. Accordingly, how to solve the problem of heat dissipation in high-power devices is always one of core problems which plague manufacturers producing high-power encapsulation devices and manufacturers using the high-power encapsulation devices.
At present, a general method for heat-dissipating comprises forced air-cooled heat radiation and liquid-cooled heat radiation. Heat dissipation of power modules such as high-power SVG (static var generator), MVD (medium-high voltage inverter), UPS (uninterruptible power supply), PCS (power converter) uses the forced air-cooled heat radiation mode; and heat dissipation of power modules such as wind power converter and high-iron drive converter uses the liquid-cooled heat radiation mode.
Air-cooled radiators are typically aluminum-extruded radiators having multiple aluminum heat dissipation fins disposed on an aluminum alloy substrate, plug-in radiators and shovel radiators. Because the thermal conductivity of aluminum and aluminum alloy is less than 220 W/m·K, the fin efficiency of the heat dissipation fin is relatively low, and the thermal diffusivity thereof is poor, which cannot meet the heat dissipation requirement of high heat flux density high-power modules.
Liquid-cooled radiators are usually composed of heat-absorbing cold plates, circulating pumps, reservoirs, heat exchangers, connecting pipes and valves, etc. The system is complex, bulky, expensive, and has corrosion, fouling and antifreezing problems. Moreover, there are multiple connection heads in the system, which may result in problems of liquid leakage and system security.
Therefore, it is urgent to develop a general-purpose and efficient radiator which not only can meet the heat dissipation requirement of the high heat flux density high power modules, but also is efficient and reliable, small in size, high in cost performance and replaceable for liquid-cooled heat radiation.